Prior to the present invention, as shown by U.S. Pat. No. 3,847,867, Heath et al., assigned to the same assignee as the present invention and incorporated herein by reference, polyetherimides were made by reacting certain aromatic bis(etheranhydride) and organic diamine. Although the Heath et al. polyetherimides are injection-moldable and can be reinforced and converted to high performance thermoplastics or composites, efforts are constantly being made to improve the solvent-resistance of such shaped thermoplastics or high-performance composites.
The present invention is based on the discovery that solvent-resistant polyetheramideimides can be made by effecting reaction between aromatic bis(etheranhydride) "BPA-DA" of the formula, ##STR1## and diaminobenzanalide "DABA" of the formula, ##STR2## or a mixture of DABA and a phenylenediamine, "PDA" of the formula, ##STR3## where R is a divalent C.sub.(6-30) aromatic organic radical defined more particularly below, and R.sup.1 is a C.sub.(1-14) monovalent hydrocarbon radical or a C.sub.(1-14) monovalent hydrocarbon radical substituted with one or more radicals neutral during intercondensation.
It has been found that improved solvent resistance can be imparted to the resulting polyetheramideimide if at least 10 mol percent of DABA is used in the diamine mixture of Formulas (2) and (3) based on the total mols of DABA and PDA utilized during intercondensation with BPA-DA of Formula (1). In addition, crystalline polyetherimide can be made from DABA isomer 4,4'-diaminobenzanilide and BPA-DA isomer 2,2-bis[4-(3,4-dicarboxyphenoxy)]propane dianhydride when polymerized under neat conditions.